The present invention relates to network interface devices.
A variety of network interface devices are available which provide station protection and subscriber line termination in a single enclosure. The network interface device enclosures are installed at a customer premise in accordance with FCC Regulations to provide a demarcation point for the customer and also a test point for the customer.
Such network interface device enclosures are often divided into two chambers with one chamber being accessible to the customer and both chambers being accessible by the service provider. Incoming wires are fed into a secure chamber only accessible by the service provider. The incoming lines are connected to a terminal block assembly or other terminal connection. Each set of wires is also connected to a standard RJ11 jack. The service provider is responsible for the service lines up to the RJ11 jacks and terminal block. The house wiring or service drops into the specific facility are the property of the building owner or customer. The customer has access to the network interface device enclosure and may use a telephone or other device to check that service is provided up to the RJ11 jack.
Often, the service provider includes protection devices to provide protection on a line up to their point of responsibility. The protection and portion of the connections up to the RJ11 jack is accessible only by the service company with a female port of the RJ11 jack being accessible to the customer for testing purposes. Alternatively, protection devices may be provided in a separate compartment or enclosure accessible only by the service provider. The terminal blocks provide interconnection and cross-connection and may be provided in the same terminal blocks as the network interface device or between adjacent terminal enclosures such as one containing the protection devices and another containing the network interface devices.
One problem with this type of configuration is that equipment can be quite expensive and require considerable space. In some situations, protection devices are not required and only the network interface devices are used.
Another problem with the currently available network interface devices is that such devices use one RJ11 jack and the appropriate connection for each set of wires. This configuration for the network interface device requires substantial expense and considerable space for housing such RJ11 receptacle and connections. RJ11 jacks and connectors cost approximately $4-$5 per unit and even in small groups, for example, approximately 10 RJ11 jacks, add a considerable cost to such equipment.
An additional consideration with prior art network interface devices is that the RJ11 jacks are active devices coupled directly to the incoming lines. As such, the RJ11 jacks are active devices. Such network interface devices perform satisfactorily in an indoor setting but can become damaged in outdoor settings. In the outdoor setting, RJ11 jacks are exposed to detrimental environmental conditions, and as a result of being active devices, tend to deteriorate at an accelerated rate. Corrosion, dust, dirt and moisture tend to accumulate in the RJ11 jack. In an attempt to overcome the environmental problems environmental protectors including, caps, plugs and sealing substances have been provided to attempt to seal the RJ11 female port. However, as a result of being an active device, corrosion may be delayed by such protectors, but not prevented.
In an electrical sense, an RJ11 jack, being part of the circuit, may introduce noise into the system. If a jack becomes damaged, it may produce a break in the connection thereby requiring additional service calls and service effort to investigate, and possibly repair or replace the RJ11 jack.
Further, the general requirements of the network interface devices are dictated by the FCC and are required to be provided by service providers for services coming into a premises. An example of such devices are RELTEC Corporation, Reliable Electric Division's Sentinel.RTM. Network Interface Device, the NID/RPT series Network Interface which provides access and connection for up to 100 pair, and the OBTNID series multi-pair Network Interface for up to 200 pair.